National Repository of Grey Literature 46 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
The impact of vertical distribution of zoobenthos in a pond in response to the biomass stocking of carp ponds
VÁLEK, Pavel
The impact of vertical distribution of zoobenthos in a pond in response to the biomass stocking of carp ponds was tested in the Rod, Dobrá Vůle, Pohořelec, Haslauerteich and Neuteich ponds. Except for the Rod pond, various carp biomass was represented in all ponds. Sampling was conducted during the growing season (June and July), and outside the growing season (September). Physico-chemical parameters of water were measured for each sample. All samples were sorted by groups, counted and weighed. The results are presented in graphs. Zoobenthos density of the Dobrá Vůle, Haslauerteich and Neuteich ponds showed a rising tendency towards deeper parts of the pond sediment. The density of these ponds reached the maximum values in depths of 10-14 cm. This tendency was observed in the occurrence of midges in these ponds. The highest density of midges was observed in the Haslauerteich pond (1,687 individuals per square metre). The above-mentioned ponds were stocked by the common carp (K2-3). The largest density of the tubifexes in the Dobrá Vůle, Haslauerteich and Neuteich ponds was observed during the September sampling in the shallow parts of the sediment (0-6 cm). The maximum density was 1,031 individuals per square metre. On the Pohořelec pond, the occurrence of zoobenthos during both samplings was recorded only in the depth of 10-12 cm. Other representatives of zoobenthos were present in the Rod, Haslauerteich and Neuteich ponds. Larvae of Sialis and Chaoboridae were observed as well. The density and biomass was greater in the September sampling. We have noticed a greater settlement in various depths. Their maximum density was in the Haslauerteich pond (218 individuals per square metre).
Feeding ecology of freshwater Heteroptera (Nepomorpha)
Šretrová, Martina ; Sacherová, Veronika (advisor) ; Kment, Petr (referee)
This bachelor thesis focuses on the aquatic Nepomorpha living in freshwater, especially on the most common representatives from families, which we can find in the Czech Republic. The main theme of this work is the mapping of the feeding ecology of water-bugs. Various feeding strategies can be observed, such as phytophagy, carnivory and omnivory. The most important strategy used by most water-bugs is predation. This behavior is related to morphological adaptations, such as modifications of the mouthparts and forelegs. Ways of obtaining and processing prey are described in detail. A special chapter is dedicated to the Corixidae family, which differs morphologically. Also the importance of predatory water bugs in the ecosystem is discussed here.
The impact of vertical distribution of zoobenthos in a pond in response to the biomass stocking of carp ponds
VÁLEK, Pavel
The impact of vertical distribution of zoobenthos in a pond in response to the biomass stocking of carp ponds was tested in the Rod, Dobrá Vůle, Pohořelec, Haslauerteich and Neuteich ponds. Except for the Rod pond, various carp biomass was represented in all ponds. Sampling was conducted during the growing season (June and July), and outside the growing season (September). Physico-chemical parameters of water were measured for each sample. All samples were sorted by groups, counted and weighed. The results are presented in graphs. Zoobenthos density of the Dobrá Vůle, Haslauerteich and Neuteich ponds showed a rising tendency towards deeper parts of the pond sediment. The density of these ponds reached the maximum values in depths of 10-14 cm. This tendency was observed in the occurrence of midges in these ponds. The highest density of midges was observed in the Haslauerteich pond (1,687 individuals per square metre). The above-mentioned ponds were stocked by the common carp (K2-3). The largest density of the tubifexes in the Dobrá Vůle, Haslauerteich and Neuteich ponds was observed during the September sampling in the shallow parts of the sediment (0-6 cm). The maximum density was 1,031 individuals per square metre. On the Pohořelec pond, the occurrence of zoobenthos during both samplings was recorded only in the depth of 10-12 cm. Other representatives of zoobenthos were present in the Rod, Haslauerteich and Neuteich ponds. Larvae of Sialis and Chaoboridae were observed as well. The density and biomass was greater in the September sampling. We have noticed a greater settlement in various depths. Their maximum density was in the Haslauerteich pond (218 individuals per square metre).
The effect of direct predation by fish on cercarial populations of selected trematode species (Digenea)
HEINCLOVÁ, Pavla
The predation effects of four fish species on the consumption of free-living cercariae of three trematode species (Plagiorchis elegans, Echinoparyphium aconiatum and Trichobilharzia szidati) were experimentally investigated with regard to specific life-history traits of both predator and parasite. The study provides evidence of a considerable consumption of trematode cercariae by fish and confirms that cercariae play an important ecological role in the energy flow in aquatic food webs.
Feeding ecology of freshwater Heteroptera (Nepomorpha)
Šretrová, Martina ; Sacherová, Veronika (advisor) ; Kment, Petr (referee)
This bachelor thesis focuses on the aquatic Nepomorpha living in freshwater, especially on the most common representatives from families, which we can find in the Czech Republic. The main theme of this work is the mapping of the feeding ecology of water-bugs. Various feeding strategies can be observed, such as phytophagy, carnivory and omnivory. The most important strategy used by most water-bugs is predation. This behavior is related to morphological adaptations, such as modifications of the mouthparts and forelegs. Ways of obtaining and processing prey are described in detail and the influence of predators on their prey is discussed. A special chapter is dedicated to the Corixidae family, which differs morphologically and ecologically from other families.
The support of occurrence of beneficial organisms in the orchards: certified methodology
Holý, Kamil ; Falta, Vladan ; Kovaříková, Kateřina ; Šenk, Jan
The publication is intended for the fruit growers and was worked upon the base of the results of the projects NAZV QJ1210209 a RO0416. It contains information about important beneficial organisms and possibilities of their support in orchards.
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The response of Marsh Frog (\kur{Pelophylax ridibundus}) to the presence of alien predators
KROUFKOVÁ, Michaela
This study focuses on the antipredator strategies of amphibian larvae in relation to some of their predators. Namely, the relationship between the larvae of the marsh frog (Pelophylax ridibundus) and the invasive species of the fish, the topmouth gudgeon (Pseudorasbora parva). Latter part of the experiment involves investigation into the relationship between another non-native species, the three-spined stickleback (Gasterosteus aculeatus). Both are non-native species of small fishes. The topmouth gudgeon was introduced unintentionally in the 1980s from Hungary. It is listed on the Black List of the Czech Republic and it is on the list of invasive non-native species of the EU Regulation (1143/2014), (Kuřátko, 1998; Poláková et al., 2016). The three-spined stickleback was brought into our territory from America. It was probably released into local ponds by Czech aquarists at the beginning of the 20th century. It is a species that is not listed on the Black List of the Czech Republic, but its negative impact on fish fry has been previously documented (Poláková et al., 2016). Both species have been known for a negative impact on the biological diversity of our fauna, but the influence of these predators on our amphibians has not so far been documented. The experimental part investigates the damage of tadpoles caused by these non-native fishes and the defensive strategy of the tadpoles. The tadpoles were provided with a hiding place as one of the possible escape strategies against the predator.
Hejnové chování jako odezva na změny prostředí, přehledová studie
JAKŠ, Jiří
The aim of my bachelor thesis was to create a review about effect of some parameters on shoal of fish. In my thesis may be found information about effects of different parameters on shoal of freshwater, marine and aquarium fish species. Review describes several parameters that effect fish in several ways and it is also contains a lot of information about shoal behaviour in general. Review gradually passes from general definition of shoal, creation of shoal, types of shoal, advantages and disadvantiges of shoal, communication and recognizing of fish inside the shoal, to enumeration of parameters that effect fish both positively and negatively. In conclusion may be found possibilities of modeling fish and their behaviour on two model examples. Information come from Czech literature, but also from foreign literature, which makes my thesis more creative and objective. Shoal behaviour is still relatively unexplored topic and many questions still remain unanswered. Exploring and assesing of shoal behaviour is relatively complicated, therefore the answers are only author´s opinions and several experiments results. Although there are speculations about this topic, many authors and experiments have similar opinion. My bachelor thesis may appreciate those, who want to know more about the shoal behaviour. In future it is necessary to realize more research about shoal behaviour and fish modeling because of its use and and less public awareness.
Should there be fishes in the water? - Ecological Educational program on the importance of water bodies without fish
BEČKOVÁ, Andrea
Water reservoir can be found anywhere in the nature. Small ponds without fish are difficult to be found. Biology students, members of biologically interested societies or wider public who is interested in environment can benefit out of these waters to learn more about relations between particular species, water and littoral plants and interactions between ranges of organisms. Fishing and fish farming do not have negligible impact on nutrition and relaxation of humans, but also they do not have negligible impact on life in waters Nowadays, the overly extended fish population is becoming the main problem that is causing fis predation which decimates pond environment. Fishless ponds are very important to provide environment for other aquatic insects and other organisms. It would be beneficial to devote more attention to the fresh water organisms at the school education through education programs or interest workshops and to have sufficient amount of suitable education resources. In this thesis, I describe relationships between organisms in fresh water reservoir, their relations with surroundings, which factors are influencing them and have impact on their occurrence.
The acoustic detection of potential predator in domestic horse (Equus caballus)
Vidimská, Tereza ; Komárková, Martina (advisor) ; Fuchs, Roman (referee)
Equidae belong to a group of large herbivores, which survival in natural environment depends beside others on their capability of fast predator recognition and detection. They can sensually recognise a possible threat in advance and react by immediate escape, which increases their survival. Also domestic horses still show very sensitive reaction to sudden (unexpected) stimuli. So we assume, that the ability to detect predator immediately is conserved despite of the long domestication process. The supportive indirect evidence is given by the successful breeding of the feral herds all over the world. However, studies showing the direct reaction of domestic horse toward the canids (as the most common predators), are still absent. Aim of the work was to find, if the horses (Equus caballus) could recognize acoustic sign of dogs like predators and if they could recognize the level of potential threat according to the number of predators, similarly as their wild ancestors. The recordings of barking of big dog breeds were obtained and modified. The final recording contained the set of barking coming from one individual or three different. The recording was played to the experimental horses, under controlled conditions, together with white sound as a control. The reactions were recorded. Altogether 12...

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